1. Field of the Invention
The present invention relates generally to an image forming apparatus capable of performing both copying and printing operations, and more particularly to a composite apparatus provided with a host computer, a copier, and a printer operable in response to instructions from the host computer.
2. Description of the Prior Art
Because laser printers are extremely superior in definition of images, they are in wide practical use today as an output device for word processors or image editing apparatus capable of preparing and editing diagrams, figures, patterns or the like on a CRT display. However, the laser printers used for this purpose are generally small-sized low-speed machines having a printing speed of about 5-6 sheets/min. One reason for this is that manuscripts prepared by word processors or the like are generally not so long and it is quite rare that manuscripts having several hundred pages or more are prepared by the word processors. Accordingly, the time required for printing is relatively short. Another reason is that high-speed laser printers are much more expensive than word processors or the like. When a number of transcripts are required from a manuscript prepared by a word processor or the like, the manuscript is initially printed by the use of any suitable printer, and thereafter, a required number of copies are generally prepared by the use of a high-speed copier, thereby causing an operator trouble.
To solve this problem, a composite apparatus having composite processing functions has been proposed, which is provided with a printer and a copier and in which a document prepared by the printer is conveyed to a document platform of the copier and is copied by the copier.
However, when a plurality of transcripts are required, composite processing cannot always minimize the time required for transcription. In other words, when the required number of transcripts is small, the sole use of the printer can occasionally make such time shorter than the composite processing.
The terms "transcript" and "transcription" are used to denote any of copies and prints and any of copying and printing operations, respectively, unless specified.